氧化镁在不同养护条件下水化产物的形貌分析

The morphologies of brucite formed from MgO hydration under different curing conditions were studied. The results showed that there were relations between the morphologies of brucite and its forming conditions. The size of brucite crystals increased with the curing time, and they were fiber-shaped at lower curing temperature and stick-shaped at higher temperature. When MgO was cured in paste with 10 percent cement, the crystal of brucite was fiber-shaped, while cured in paste with 95 percent cement, the crystal was hexaflaggy-shaped, which aggregated and produced some micro-cracks in paste when the curing temperature was increased. At 180 ℃ autoclaving temperature of MgO, the brucite was regular hexaflaggy-shaped crystal; for 216 ℃, it was less irregular. When the paste mixed with 50 percent fly ash, the crystal of brucite was needle-shaped and distributed more evenly, so decreased the deformation and crack of the concrete.     

混凝土高坝裂缝光纤分布式监测能力的研究

基于单点裂缝模型试验结果分析,提出了一种利用瑞利散射的工程结构裂缝光纤监测复用能力的方法,得到水工混凝土裂缝光纤监测两种典型方案的裂缝复用能力,结合三峡工程泄洪坝段上游面出现的裂缝,进行了光纤裂缝传感复用能力的工程适用性分析,进一步揭示工程裂缝光纤分布式监测能力研究的意义.     

泡沫轻质混凝土性能与孔结构关系研究

为满足工程应用需要,针对600 kg/cm~3和800 kg/cm~3密度等级的泡沫轻质混凝土,分析了不同密度和水胶比时的抗压强度与孔结构关系。研究结果表明,泡沫轻质混凝土的平均孔径随水胶比增大而增大;泡沫轻质混凝土平均孔径随密度等级升高而下降,当密度等级从600 kg/cm~3增大到800 kg/cm~3时,平均孔径变化约为24.5%～25.4%,孔隙率变化约为2.8%～16.6%;抗压强度随水胶比增大呈先增大后下降的趋势。